Present supplemental restraints including deployable knee bolsters and air bags are used in motor vehicles to provide occupant protection by providing a reaction element that resists the motion of an occupant in a controlled manner during an impact. Airbags are inflatable and are commonly used to provide increased occupant protection for the torso and head. Knee bolsters are deployed to help resist forward movement of the knees and thighs. Knee bolsters can also be inflatable, but commonly include molded plastic bladders and when fully deployed occupy much less volumetric space than an airbag. Some present knee bolsters reposition a vehicle trim component into a knee area of a passenger compartment upon detection of a collision. Once deployed, present supplemental restraints, especially inflatable supplemental restraints, need to be replaced and associated interior trim components may also need to be replaced. Present supplemental restraints are controlled by and selectively activated by an electronic control unit that receives signals from sensors, and processes such signals using software control logic stored in the electronic control unit. The electronic control unit sends out command signals to the supplemental restraints responsive to the signals received and the control logic.
The availability of supplemental restraints and the deployment control command logic each vary with seating position. Use of supplemental restraints for rear seat positions is presently more limited than for front seat positions.
Possible changes in vehicle interiors, including front seats rotatable to rear facing positions as may be enabled by autonomous vehicles, and increased supplemental restraints in rear seats, are rendering current sensing systems and deployment logic inadequate for future vehicle configurations. It is desirable to provide improved occupant sensors and improved supplemental restraint deployment control command logic suited for used with future vehicle configurations.